Electronic tube structures



Max-c113, 1959 T. K. RIGGEN 2, 7

' ELECTRONIC TUBE STRUCTURES Filed April 11, 1955 2 Sheets-Sheet 1INVENTOR. 7000z A? 19/665 WW nmPme March 3, 1959 T. K. RIGGEN 2, ,3

' ELECTRONIC TUBE STRUCTURES v Filed April 11, 1955 2 Sheets-Sheet zELECTRONIC TUBE STRUCTURES Theodore K. Riggen, Elmira, N. Y., assignor t'Corning glais Works, Corning, N. Y., a corporation of New ApplicationApril 11, 1955, Serial No. 500,430

11 Claims. (Cl. 313-102) This invention relates to electronic tubes ofextremely small size, and more particularly to a design for such tubesthat lends itself well to multiple tube elements as a singlemanufactured piece.

The present state of the electronic arts requires miniaturization 'ofall its components. A further requirement is that the several componentsbe so designed that multiple elements can be manufactured. An example ofthis type of design is the trend to printed circuits and modularconstruction. It is the prime object of this invention to so change thebasic design of electron tubes that these conditions will be met.Electron tubes, as currently being produced, consist of small metallicparts (usually welded together) encapsulated in a hermetically sealedcontainer. The minimum sizes in which they can be made is dictated bythe sub-assembly of the metallic parts and the physical handlingthereof. The inability to multiplex these units is inherent in theirindividual encapsulation. The present invention avoids both theseparameters by the nature of its design which can best be understood byreferring to the accompanying drawings wherein:

Figure 1 shows an exploded view, in perspective, of a single diode builton the principles of the present invention.

Figure 2 is an exploded view, in perspective, of a triode of the samedesign.

Figure 3 is an exploded view, in perspective, of a grid controlledindicator tube of like design.

Figure 4 is a cut-away view of a multiple element array of indicatortubes with dual grids for control.

Figure 4a is a circuit diagram applied to elements of the structuralarrangement of Figure 4.

Figure 5 is a cross-sectional view of the unit shown in Figure 2,assembled.

Figure 6 is an application of the triode of Figures 2 and S to a commontype of resistor-coupled amplifier circuit, with the supports for theseveral elements of such triode omitted to simplify the showing;

Figure 7 shows a circuit, similar to that of Figure 6, employing aconventional triode.

Referring now to the diode shown in Figure l, 11 is a supporting memberof some stable insulating material such as glass; 12 is an electronemissive coat on the fore face of 11. This may be a semi-transparentphotoemissive coat adapted to receive exciting light through support 11from the opposite side thereof; it may be a thermo-emissive coat adaptedto receive infra-red radiation through the supporting member; or it maybe thermoemissive, heated by aiesistance coat (not shown), on the sameface of the support. A conducting foil, 13, is atfixed to the electronemissive coat and acts as the cathode connection of the diode. A spacerplate 14 separates the cathode 12 from an anode supporting plate 16 thedesired distance. A hole 15 in plate 14 allows electrons from cathode12, to pass to an anode 17, which is sealed in plate 16.

atent ice Plate 28 has a hole 29 in register with a hole in plate 24,and bears foil 20 which surrounds hole 29 and extends beyond an edge ofplate 28. Foil 20, when held at a negative potential, acts as a gate, orgrid, to regulate the number of electrons passing from the cathode 22,to an anode 27 supported by a plate 26, similar to plate 16.-

Hence a triode is obtained. The addition of a second member similar tothat formed by elements 20, 28 and 29 could yield tetrode action, etc.,as will be understood by those familiar with the construction andoperation of electron valves or tubes.

In Figure 3, a plate 36, which bears a fluorescent powder coating 32 onthe side next to a plate 34, replaces the plate 26 of Figure 2. Thiscoating is of the conducting type and connection'to it is made through afoil 33. Elements 31, 34 and 38 are like the elements 21, 24 and 28 ofFigure 2.

In Figure 4 (Sheet 2), the plate 411 bearing'fluorescent coating 412,connected to foil 413, is functionally similar to the like elements inFigures 1-3. Plate 41, having holes such as 45, is substantially asdescribed in Figure 1.

' Plate 48, having holes 49 surrounded by grid electrodes grammaticallyshown with push button switches B1-B14 associated with their respectivegrids, normally placing a negative bias thereon.

In Figure .5 (Sheet 1) the unit shown exploded in Figure 2 isillustrated assembled, and has its corresponding elements designatedlikewise. This is, then, indicative of the other embodiments of thepresent invention in assembled form whether they be of the single ormultiplex type. A material such for example as solder glass 50 has beenadded to seal the lines of juncture of the several plates together afterevacuation. The respective plates may, however, be directly sealed toone another providing the dielectric material used has a low enoughsoftening temperature to enable the sealing of their adjoining-surfacesto one another without harm to the coatings thereon. Under suchcircumstances, where some types of coatings are used, to assureobtainance of hermetic seals between the coated and uncoated plates itis necessary that the outer margins of the coating terminate a shortdistance from the plate edge so that glass-toglass contact is obtained.A further alternative is to employ a form of encapsulation of theseveral forms currently in use in vacuum tube practice. From the showingin Figure 5 it will be noted that the inner end of the anode 27terminates short of the entrance to a pocket 51 in plate 26. Obviously,if desired, a plate similar to 26, having the added thickness of spacerplate 24, can be employed in lieu of plates 24 and 26, thus reducing thenumber of joints in the seal. The operation of a single cell tube canbest be explained by references to Figures 5 and 6.

Light striking through plate 21, Figure 5, causes electrons to beemitted by photo-emissive cathode 22. These electrons will proceed atrandom velocities and directions away from cathode 22 in the evacuatedspace left .by holes 29 in. plate 28, and 25 in plate 24 and/or pocket51. If the anode 27 is held at a positive potential, with respect to thecathode 22, the emitted electrons will be drawn to the anode, 27 and acurrent will be established. A controlled potential applied to gridfoil'20 will control the flow of electrons from the cathode 22 to theanode27. The action of a circular grid member is well understood bythose acquainted with cathode ray tube electron guns. "7

For a comparison of a co ventional circuit employing a tlide tubeembodying the invention with a tube of conventional form, reference ishad to Figures 6 and 7. In Figure 6 a light source L, powered by abattery 6A exciters the photo cathode 22. In Figure 7 a heater H,

powered by a battery 7A, excites the therrno-emissive cathode K. InFigure 6 a battery 63, through a load resistor, 6R2, maintains the anode27 at a positive potential with respect to the cathode. In Figure 7 abattery 73, through a load resistor 7R2, eflects the anode P in asimilar fashion. In Figure 6, a battery 6C, through a resiSiO F 6R1,maintains the grid 20 at some optimum negative bias with respect to thecathode. In Figure 7 a battery 7C, through a resistor 7R1, effects thegrid G in a similar fashion. Now, if an A. C. voltage signal beimpressed across the input points, GIN or 7IN, and read across theoutput points, 6OUT or 7OUT, it will have been amplified by the gain ofthe system.

In the case of the triode circuit in Figure 7 the gain of the system is,in part, a function of the potentials applied, the component valuesused, the geometry of the triode and the emissive ability of the cathodein the triode. The same parameters hold for the triode used in Figure 6.I

The geometry of the new design tube may be altered by changing the sizeof the holes, by expanding the inner endof the anode wire to a discequal to the hole size, and by regulating the thickness of the gridsupporting and spacer plates.

If a relatively high current unit is desired, necessitating the use oflarger plates, the grid supporting plate having a single hole may bereplaced with one having a group of small holes with but a single foilsurrounding and interconnecting them, so that the portion of the platebridging adjacent holes in the grid will serve as a mechanical supportfor the large area of the adjacent cathode plate during evacuation andsealing of the unit.

In the embodiment of a multiplex of units as shown in Figure 4, theholes in plates 41, 48 and 414 are in line to'allow electrons emitted bythe cathode 412 to pass through to the fluorescent anode 42 on the innerside of plate 46. The strip grid connections or foils 410 and 416 arecontinued past their supporting plates 48 and 414 in a fashion similarto the single unit grid 28 in Figure 2. This multi-element unit can beused for the selective display of several indicator spot signals.Similarly such a unit employing individual anodes, such as 27, may .beemployed in selective control circuits as hereinafter described.

By Way of example, with respect to selective indicator signals,reference is had to Figure 4a wherein plate 414 has a bank of forty-nineholes divided into seven rows of seven holes each, with its grids 416horizontally connected. Each row of grids 416 is normally heldsufficiently negative with respect to the cathode 412 (Figure 4) toprohibit the passing of electrons from the electronemissive coating 412on plate 41, by negative potential supplied to it through the backcontacts of a push button, such as B1, of the group B1B7. Similarlyplate 48 has its grids 410 vertically connected in seven rows negatively biased through break contacts of push buttons B8-B14. As will beevident any one or more .of the push buttons of the respective pushbutton groups may be operated to selectively remove the negative biasfrom any row or rows of holes in either of the multi-element grid plates48 and 414 to permit electrons to pass through the particular holes inregister with one another and from which the grid bias has been removed.By way of example, if buttons B1 and B8 are depressed electrons will bepermitted to pass through holes X and Y, and when they strike the anodeor fluorescent coating 42, the spot or spots on the anode opposite suchholes will fluoresce and thus give an indication of the vertical andhorizontal row or rows of grids thatare not biased down. Obviously theshowing of the grid control circuits as passing through push buttons isfor simple illustrative purposes only. As is well known, there arenumerous ways in which the grid bias can be removed in any desiredcombination to selectively give a number of different indicationslimited only by the number of separate electronic tube units embodied inthe assembly.

Alternatively, the multiplexing mayemploy individual anodes, such as 27,and follow a pattern in conformance with a desired specific circuitcontrol need. For example the unit may contain a single row of cellsarranged to register with the holes in a teletype-writer tape so thatlight passing through the tape holes selectively activates the cells asit passes thereover to selectively energize printer control relays ofthe system.

A further alternative arrangement may embody both the individual anodessuch as 27 and a fluorescent coating such as 42, to give a visual signalof the circuit control being exercised.

In addition, as will be evident, if desired the several plates ofdielectric material of the-assembly may be utilized as the supports forsimple printed circuits in which such cells may be included.

What is claimed is:

1. An electronic tube comprising a stack of plates of insulatingmaterial one outer plate of such stack having on its inner surface acathode comprising a coating of an electron emissive material, saidcoating having a lead conductor connected thereto and extendinglaterally therefrom, the oppositely disposed end plate having an anodeexposed on the opposite broad surface thereof, and an intermediate plateof said stack spacing the anode and cathode a predetermined distancefrom one another, said intermediate plate having a passage therethroughproviding a path for the flow of electrons between the cathode and theanode.

2. An electronic tube such as defined by claim 1, wherein the stackincludes an electron gate comprising a plate of electric insulaitngmaterial arranged between the cathode and the intermediate plate andhaving a passage therethrough in register with the intermediate platepassage, said electron gate plate having on the side thereof facing saidintermediate plate a conductor bordering its passage and extendingbeyond the edge of such plate to make it available for the receipt of anegative potential to regulate the number of electrons that arepermitted to pass between the cathode and the anode.

3. An electronic tube-comprising a stack of plates of electricalinsulating material one end plateof such stack having on its innersurface a cathode comprising a coating of an electron emissive material,the oppositely disposed end plate having on its inner surface an anodecomprising a coating of a fluorescent material, said coatings havinglead conductors connected thereto and laterally extending therefrom, aspacer plate arranged between said end plates having an aperturetherethrough for the passage of electrons between said anode andcathode.

4. An electronic tube such as defined by claim 3 wherein the stackincludes. a plate interposed between the first defined end plate andsaid spacer plate having a layer of conductive material thereonsurrounding a passage therethrough in register with the spacer platepassage on the side adjacent the spacer plate, said conductive materialextending from the edge of such plate to make it available for thereceipt of a negative potential to regulate the number of electrons thatare permitted to pass between the coated surfaces of the end plates ofthe stack.

5. An electronic device including plates of an electrical insulatingmaterial forming the opposite end plates of a stack thereof, one of saidend plates having a cathode comprising a semi-transparent photo-emissivecoating on its inner surface, the other ,end plate having an anode on tsinner surface comprising a fluorescent coating, a spacer plate includedin said stack, two electron gate supporting plates arranged adjacent oneanother between said spacer plate and one of the end plates, said spacerplate and said electron supporting gate plates having a plurality ofapertures in register with one another and providing a number ofseparate electron paths between said end plates, and means forselectively controlling the flow of electrons through such passages toexcite corresponding surface areas of the anode.

6. In an electronic tube, a stack of flat plates of an electricalinsulating material hermetically sealed together, a cathode arranged onthe inner surface of one end plate of such stack, an anode supported bythe opposite end plate of the stack, and a spacer plate between said endplates having an aperture providing an electron path between said endplates.

7. An array of electron tubes wherein the like electrodes of all thetubes are carried on a single plate of insulating material.

8. In an electronic tube, a plate of an electrical insulating materialhaving on one broad surface a cathode coating, a second plate having apocket in a broad surface thereof opposite said cathode coating, and ananode passing through the latter plate having an end terminating Withinsaid pocket short of its entrance.

9. An electronic device including plates of an electrical insulatingmaterial forming the opposite end plates of a stack thereof, one of saidend plates having a cathode comprising a semi-transparent photo-emissivecoating on its inner surface, a plurality of anodes supported by saidother end plate, a spacer plate included in said stack, two electrongate supporting plates arranged adjacent one another between said spacerplate and one of the end plates,

said spacer plate and said electron supporting gate plates each having aplurality of apertures in register with one another and in register withsaid anodes providing a number of separate electron paths between saidfirst end plate and said anodes, and means for selectively .controllingthe flow of electrons through such passages to selectively excitedifierent ones of said anodes.

10. An electronic device such as defined by claim 9, wherein said otherend plate is also provided with a fluorescent coating which fluorescesin the region surrounding the excited anode or anodes to visuallyindicate the selection made.

11. An electronic tube such as defined by claim 1 wherein the respectiveplates of the stack have oppositely disposed flat parallel surfaces inengagement with one another and have border outlines in the samevertical planes, and a layer of material bridging the respective layersof the stack and sealing the regions thereof surrounded by such materialand between the inner surfaces of the end plates thereof to atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS2,099,531 Passarge Nov. 16, 1937 2,297,492 Michaelia Sept. 29, 19422,449,493 Longini Sept. 14, 1948 2,533,809 Hershley et al Dec. 12, 19502,592,683 Gray Apr. 15. 1952 2,645,712 Rajchman et al July 14, 19532,657,309 Gray Oct. 27, 1953 2,754,445 Sorg July 10, 1956

